双兔傍地走，安可辨雄雌？

checkmoteur

上面周兄谈及以髋关节为轴转腿，究竟是什么样子的问题，俄刚才看section8的一个视频时，意外发现一个好例子，比华伦老兄那个还简单直观：

checkmoteur

这个小视频把上面那个又剪短，基本上是背拍一个小弯的phase1、phase2，就是说从上一个弯的release，到下一个弯的上刃加压之前。重复四遍：

我想这表现得非常清楚，how visually，这位爷在主动能动地转动他的雪板。

视频仍有争议，那就剩上静态序列图一个办法了：

这幅图来自这位爷的名著，Anyone can be an expert skier 2，表现的是用phantom move滑bump的一个弯。

注意序列中的b，tipping内脚，开始phantom move，到d，雪板接触雪面的瞬间，他雪板的朝向，是怎样地向圈内偏移了近45度。

Oh come on，don't tell me that's caused by the side-cut of the skis！这可是滑包包，b到d之间，雪板根本是在空中飞。不是转腿的话，难道side-cut与空气碰撞，挤压出反向chamber，导致雪板自转？

到这一步，你还需要更多的论证的话。论证也就到此为止吧。你已选择拒绝，论证再多也没用。

Phantom move，就是转腿，steering。这是rather高明的转腿技巧，至少比靠肌肉硬转高明。但再高明，还是转腿而已。

我说我写着玩，不代表我不认真。我不太拿自己当前的结论以为然，只因为知道自己水平不够，不说明我态度不严肃。

checkmoteur

上面那个表述有误。俄想正确的说法是Phantom move既可以制造纯edging，result in一个所谓纯carving，也可以制造leg rotation，转腿，result in一个steered的turn，在那些必须使用steering去完成一个弯的场合，比如小弯，和上图的bump。

滑bump不转腿是无法想象的，因为滑行于蘑菇间的路线已被地形规定住了。你当然有得选择，可以搓顶，走谷，甚至走zipper line，看你水平。但这些选择极为有限，且无论哪种，都不是你单纯立刃压板，就能manage的。除非again，你脚下踩得是一对snowblades，甚至冰刀。

The point is，如前面或别的地方反复说过的，滑雪的基本运动方式就两种，转雪板，或让雪板转。软性的场合如个人意愿，硬性的场合如地形和turn shape的要求，你总需要在两者间选择一种，或者不同程度地杂糅二者。一种方式通吃，不可能。

下图同样来自那本书，且就是上面那个序列图的紧凑版，从而可以更清晰地看出，从下数第二帧开始，到下数第四帧结束，经过了一整个phantom move之后，雪板指向的向内变化，是如何的dramatically，而绝无任何雪板的self-steering effcet involved：

Epicski上另外一个人论述类似观点的内容如下，只是观点的节选，因为论证从人体医学角度出发展开的，俄实在不懂：

The result of this is that people think that PMTS has no rotation component to it. The reality is the strongest bio-mechanical way to apply twisting torque to the outside leg is with the phantom move.

The little dark secret that some people in the PMTS camp ignore but Rusty Guy has observed is that this move creates rotary torque in the other leg. This means you can use it for hop turns, bumps, etc. You can also over do this move and create a very skidded non-carved turn. (Rusty's observation of some skiers he is calling PMTS). This shouldn't be a secret because there is nothing wrong with this. Match this controllable rotation to what the skis are doing and you carve, go to the other extreme and you hockey stop.

In doing the phantom move, you start with your skis parallel. You tip the inside foot. If your hips are relaxed and not in a co-contracted state you will feel absolutly nothing happen on your other leg. However, if you apply a little, and just a little of that co-contracted feeling to your hip-rotators so that you have told your hips and rotators maintain position, when you tip that inside foot you'll almost feel your other foot tear the rotational torque is so strong. The only way to relieve the pressure is to let that leg and foot tip also or rotate.

Whenever a PMTS skier using the phantom move is tipping the inside foot and in an o-frame so there is a momentary differential of angles of the shins (bowlegged a tad) while maintaining some hip-rotator tension, they are going to be creating rotational torque on the other leg. Once the legs are aligned again then you have no rotational torque on the outside leg.